Big state hashTreeRoot() time in lodestar

### Problem description

state hashTreeRoot() takes up to 1s - 1.5s frequently, need to find a way to improve it

this is likely to happen after processing an epoch, in rare case it could be up to 1.8s on holesky #6194

### Solution description

Reduce it as much as possible
- Improve our hash function either by SIMD [here](https://github.com/ChainSafe/ssz/issues/356) or (most likely) [hashtree](https://github.com/ChainSafe/ssz/issues/355) work by @wemeetagain
- Find a way to consume it in persistent-merkle-tree

### Additional context

_No response_